Research

Compounds of FOTDA series were designed and studied as chiral components of high-performance ferroelectric liquid crystal (FLC) materials targeted on high demand applications in display and photonic devices. Combination of high twisting ability with large spontaneous polarization (PS > 100 nC/cm2) resulted in promising FLC mixtures: almost defect-free alignment in electro-optical cells, the optical quality of the cells becomes comparable to that based on nematic liquid crystals, but switching is at least in order faster (2019, doi: 10.1016/j.molliq.2019.02.047).

Dependence of twisting power in induced chiral smectic C (SmC*) mesophase on molecular structure of the FLC chiral component; key parameters and the most promising ways of practical application of the FLC material made using the diesters of p-terphenyldicarboxylic acid and chiral trifluoroalkanols.

Method for determination of the helix elastic modulus (Kh) in ferroelectric liquid crystals (FLCs) from dielectric spectra is proposed. According to the method, well away from the SmA*-SmC* phase transition, the Kh obtained for FLCs with known p0 can be used as the constant for determination of p0 which cannot be determined from the selective light reflection (2021, doi: 10.15407/fm28.04.645).

Dependence of helix elastic modulus (Kh) in induced SmC* mesophase on concentration (c) of a chiral component at different temperatures.

Derivatives of fluorinated and non-fluorinated p-terphenyl-containing symmetric tetraesters were designed and studied as chiral components (CCs) of ferroelectric liquid crystal (FLC) materials working in deformed helix FLC (DHFLC) mode. The new CCs induce short helix pitch (as short as 78 nm) and large spontaneous polarization (PS >100 nC/cm2) at moderate concentrations (as low as 12 mol. %) in a non-chiral biphenylpyrimidine host. Highest known to date value the helical twisting power in the induced SmC* phase of 101 m–1 is obtained (2022, doi: 10.1016/j.molliq.2022.119051).

Dependence of twisting power in induced SmС* mesophase on the presence and positions of fluorine atoms in molecules of the chiral component of FLC, and key FLC parameters of the material made using the chiral tetraester of p-terphenyldicarboxylic acid with lactate linkers and trifluoroalkanol residues.

Novel intramolecular recyclization under strongly basic conditions is found. The LDA-mediated new reaction occurs by cleavage of the C–S bond along with formation of the other C–S bond (2022, doi: 10.1080/17415993.2022.2050233). 

Pathways of the condensation reaction of 4-methyl-1-phenylquinolone and 3-methyl-2-(methylthio)benzothiazolium tosylate depending on relative quantity of the base (LDA): “normal” condensation, and condensation followed by recyclization of the product.